Endometrial Lipid Research Articles

Rumen-protected methionine supplementation alters lipid profile of preimplantation embryo and endometrial tissue of Holstein cows.

Our objective is to evaluate the effects of feeding rumen-protected Met (RPM) throughout the transition period and early lactation on the lipid profile of the preimplantation embryos and the endometrial tissue of Holstein cows. Treatments consisted of feeding a total mixed ration with top-dressed RPM (Smartamine® M, Adisseo, Alpharetta, GA, United States; MET; n = 11; RPM at a rate of 0.08% of DM: Lys:Met = 2.8:1) or not (CON; n = 9, Lys:Met = 3.5:1). Endometrial biopsies were performed at 15, 30, and 73 days in milk (DIM). Prior to the endometrial biopsy at 73 DIM, preimplantation embryos were harvested via flushing. Endometrial lipid profiles were analyzed using multiple reaction monitoring-profiling and lipid profiles of embryos were acquired using matrix assisted laser desorption/ionization mass spectrometry. Relative intensities levels were used for principal component analysis. Embryos from cows in MET had greater concentration of polyunsaturated lipids than embryos from cows in CON. The endometrial tissue samples from cows in MET had lesser concentrations of unsaturated and monounsaturated lipids at 15 DIM, and greater concentration of saturated, unsaturated (specifically diacylglycerol), and monounsaturated (primarily ceramides) lipids at 30 DIM than the endometrial tissue samples from cows in CON. In conclusion, feeding RPM during the transition period and early lactation altered specific lipid classes and lipid unsaturation level of preimplantation embryos and endometrial tissue.

Lipid Profiling of Peri-implantation Endometrium in Patients With Premature Progesterone Rise in the Late Follicular Phase.

Late follicular phase elevation in serum progesterone (P) during controlled ovarian hyperstimulation negatively affects the outcome of assisted reproductive technology by contributing to endometrial-embryo asynchrony. There are still no data on lipid metabolite alterations during this process. To investigate alterations in the lipid profile during the window of implantation in patients with premature P rise. Lipidomic variations in the endometrium were evaluated by ultrahigh-performance liquid chromatography coupled with electrospray ionization high-resolution mass spectrometry. University assisted reproductive medicine unit. Forty-three patients undergoing in vitro fertilization/intracytoplasmic sperm injection because of a tubal factor or male factor infertility were included in this study. The patients were divided into a high P group (P ≥ 1.5 ng/mL, 15 patients) and a normal P group (P < 1.5 ng/mL, 28 patients) on the day of human chorionic gonadotropin administration. The endometrial tissues were obtained by Pipelle biopsy 7 days after human chorionic gonadotropin administration. Alterations in lipid metabolites. A total of 1026 ions were identified, and 25 lipids were significantly upregulated. The endometrial lipid profile was characterized by substantial increases in the concentrations of phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine, diacylglycerol, ceramide, phosphatidylinositol, and phosphatidylserine in patients with a premature P rise at the end of the follicular phase. The correlation analysis between P levels and lipids showed a stronger negative correlation between phosphatidylethanolamine or phosphatidylserine and P levels. Premature P elevation disrupts the lipid homeostasis of the endometrium during the peri-implantation period. The altered lipid levels may impair endometrial receptivity and early embryo implantation.

101 SUPPLEMENTATION WITH SUNFLOWER SEED ALTERS THE ENDOMETRIAL LIPID COMPOSITION IN BEEF COWS

Embryo death between 15 and 19 days of pregnancy is caused by the increase in the release of endometrial prostaglandin F2α (PGF2α) involved in the luteolysis process in cattle. Compounds rich in linoleic acid, such as sunflower seeds, provide lipid changes in the endometrium, and may be involved in the ability of PGF2α biosynthesis. Previous studies observed that the conception rate increased in Nelore cows supplemented with sunflower seed for 22 days from the timed AI (66.7% v. 46.3%; Peres et al. 2008, Acta Sci. Vet. 36, 639) and in crossbred heifers submitted to timed embryo transfer (55.66% v. 36.94%; Membrive et al. 2013 Acta Sci. Vet. 36, 603). We aimed to test the hypothesis that supplementation with sunflower seed promotes endometrial changes in lipid composition. Thus, we compared the composition of fatty acids in endometrial tissue in cows supplemented or not with sunflower seed. Nelore (n = 30) cows received an intravaginal device containing progesterone (1 g; DIB, Syntex Biochemistry &amp; Pharmaceutical Industries SA, Buenos Aires, Argentina) associated with an im injection of oestradiol benzoate (2 mg; Benzoate HC, Hertape Calier Animal Health SA, Juatuba, MG, Brazil). The devices were removed after 8 days, when cows were treated im with cloprostenol sodium (2 mg; Sincrocio®, Ourofino Animal Health Ltd., Cravinhos, SP, Brazil), oestradiol cypionate (0.5 mg; ECP®, Zoetis Ltda., São Paulo, Brazil) and eCG (300 IU; Folligon®, Intervet Veterinary Ltda., Cotia, Brazil). Two days after removal of the device, females were assigned into 6 groups to receive 1.7 kg/animal/day of 40% soybean meal, 44% crude protein (CP) + 60% sunflower seed for 6 (n = 4), 14 (n = 5) and 22 days (n = 6), or 53% soybean meal, 44% CP + 47% corn for 6 (n = 4), 14 (n = 5) and 22 days (n = 6). Both diets were formulated with 72% total digestible nutrients and 24% CP. Females were slaughtered 24 h after the end of supplementation and endometrial tissue was isolated and stored at –196°C. The fatty acids in endometrial tissue were assessed by gas chromatography. Data were analysed by SAS Proc GLIMMIX (SAS Institute Inc., Cary, NC, USA). The fatty acid profile (54 compounds) was analysed and 43 fatty acids were present in the endometrial tissue. The lacking fatty acids in endometrial tissue were C4:0, C11:0, C12:1, C: 13:0, C13:0 iso, C13:0 anteiso, C14:0 iso, C15:1, C18:1 trans-16, C18:2 cis-12, trans-10, and C21:0. The fatty acids that showed a higher percentage compared with the Control group were C18:1 trans-10-trans-11-trans-12 and C10:1. The fatty acids that showed low percentage compared with the Control group were C15:0 iso, C20:5, C20:3n-3, C23:0, C24:0, and C22:5. In conclusion, supplementation with sunflower seed promotes changes in the endometrial lipid profile that may reduce the pregnancy loss in beef cows. Research supported by FAPESP, FUNDUNESP, and Santa Encarnação Farm.

Changes in uterine endometrial phospholipids and fatty acids throughout the oestrous cycle and early pregnancy in the ewe

This study examined changes in ovine endometrial phospholipids and fatty acid concentrations associated with luteolysis and the establishment of pregnancy in the ewe on days 3, 12 and 15, respectively. Results from this study indicate that endometrial lipids increased as the oestrous cycle progressed from days 3 to 12 and 15, whereas during early pregnancy, endometrial lipids decreased on day 15 of pregnancy when compared to days 3 and 12 of pregnancy. Phosphatidylcholine followed a similar pattern to that of total lipids, with an increase in phosphatidylcholine concentrations as the oestrous cycle progressed. During the early stages of pregnancy, phosphatidylcholine increased from day 3 to day 12, but then returned to previous levels by day 15 of pregnancy. Phosphatidylethanolamine increased late in the oestrous cycle, on day 15 as compared to days 3 and 12. This increase did not occur during early pregnancy, with phosphatidylethanolamine concentrations being constant from day 3 to day 15 of pregnancy. Both phosphatidylinositol and phosphatidylserine followed a similar pattern to phosphatidylethanolamine during the oestrous cycle and remained constant during early pregnancy. The fatty acid content of the major phospholipids involved in prostaglandin synthesis were examined over the range of fatty acids from C14:0 to C24:1ω9. Although changes in arachidonic acid were observed, there were no clear indications that these changes were directly related to the changes in PGF 2α synthesis.

Incorporation of [ 14C] arachidonic acid into ovine conceptus and endometrial lipids

The purpose of this study was to quantitate conceptus and endometrial incorporation of [ 14C]arachidonic acid (AA) into individual neutral and polar lipids. Endometrium and conceptuses from pregnant ewes and endometrium from nonbred ewes were collected 14 and 16 d after onset of estrus (d 0). Tissues were incubated for 8 h at 37°C in medium containing 1 μCi of [ 14C]AA. Thin-layer chromatographic procedures were used to separate 12 lipids. Radioactivity was measured in each lipid, and the amount (ng) of [ 14C]AA incorporated into each lipid was calculated. Conceptuses and endometrium incorporated more [ 14C]AA into triacylglycerols than into any other lipid. Day and tissue type affected differentially (i.e., day X tissue interaction) the incorporation of [ 14C]AA into several lipids; d-14 conceptuses incorporated [ 14C]AA more actively than did any other day-tissue combination. Results indicate that triacylglycerols may be an important reservoir for conceptus and endometrial AA. The remarkable ability of d-14 conceptuses to incorporate [ 14C]AA into various lipids may be important for their accelerated elongation and active prostaglandin synthetic system.

Further studies on the control of arachidonic acid turnover in guinea-pig endometrium in relation to prostaglandin production

The amounts of phospholipids in the guinea-pig endometrium were phosphatidylcholine (PC) > phosphatidylethanolamine (PE) = sphingomyelin (Sph.) > phosphatidylserine (PS) + phosphatidylinositol (PI). There were no significant differences in the amounts of any of these phospholipids in endometrium between Days 7 and 15 of the cycle. The de novo synthesis of PC was 5- to 10-fold higher than the synthesis of PC from PE in guinea-pig endometrium. There were no differences in the amounts of PC formed by either pathway, and in the amounts of PI synthesized by guinea-pig endometrium between Days 7 and 15 of the cycle during a 6 h culture period. The increased incorporation of arachidonic acid into phospholipids of guinea-pig endometrium on Day 15 compared to Day 7 cannot be accounted for by an increase in phospholipid content or increased phospholipid synthesis on the former day. Following a 24 h labelling period of endometrial lipids with [ 3H] arachidonic acid ( 3H-AA), there was a significant decrease in the amount of 3H-AA in PC and PE on Day 15, but not on Day 7, following a further 48 h culture period. Progesterone, oestradiol and A23187 did not affect the amounts of 3H-AA released from the various lipid classes in guinea-pig endometrium during the time periods of culture studied. It is concluded that PC and PE may be the source of arachidonic acid for increased PGF 2α synthesis by guinea-pig endometrium after Day 11 of the oestrous cycle. The lack of changes in PI content and PI synthesis between Days 7 and 15 of the cycle indicates that stimulation of the PI cycle is not involved in the biochemical processes which lead to increased AA release and PGF 2α synthesis in guinea-pig endometrium after Day 11 of the cycle.

Arachidonic acid uptake into and release from guinea-pig endometrium in vitro on days 7 and 15 of the oestrous cycle

Endometrium from guinea-pigs on Days 7 and 15 of the oestrous cycle (days of low and high endometrial prostaglandin F 2α production, respectively) was maintained in tissue culture for periods up to 24 h (uptake experiments) or 48 h (release experiments). Tritiated arachidonic acid ( 3H-AA) was incorporated into endometrial phospholipids and neutral lipids in a time-dependent manner. After 24 h of culture, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were the major phospholipids, and triglyceride (TG) was the major neutral lipid which had incorporated 3H-AA. PC, PE and phosphatidylserine/phosphatidylinositol (PS/PI) incorporated significantly more 3H-AA on Day 15 than on Day 7. TG also incorporated more 3H-AA on Day 15 than on Day 7, but the increase was not statistically significant. Tritiated oleic acid ( 3H-OA) was incorporated into endometrial phospholipids and neutral lipids in a time-dependent manner. No increase in uptake of 3H-OA occurred on Day 15 compared to Day 7. There appears to be a specific stimulation of the mechanisms involved in the uptake of arachidonic acid into guinea-pig endometrium (particularly into the phospholipids) at the end of the oestrous cycle. There was little apparent release of 3H-AA from any endometrial lipid class, except diglyceride (DG) and monoglyceride (MG), on Day 7. In contrast, there was an apparent 50 to 80% decrease in the 3H-AA content of several endometrial lipid classes, particularly PC, PE and TG, on Day 15. Overall, the uptake and release studies suggest that PC, PE and possibly TG form the source of free arachidonic acid for PGF 2α synthesis by the guinea-pig endometrium.

Endometrial lipid inclusions in the estrogen stimulated uterus.

Cytochemical studieshave been made of the uterine epithelium of ovariectomized mice, with and without estrogen stimulation.The incorporation of malachite green into a glutaraldehyde fixative has made possible the retention and visualization of a granule population in the apical epithelium of estrogen stimulated mouse endometrium that has not been previously described. These granules range in excess of 1 �m in diameter and appear to be released into the uterine lumen. It is suggested that this granule pattern may reflect the biochemically described increase in phospholipid metabolism afterestrogen stimulation. In the absence of estrogen stimulation,the appearance of lipid granule patterns in the endometrium of spayed mice was consistentwith earlier reports.

Effect of an intrauterine foreign body on [formula omitted] incorporation of acetate- 14C into endometrial macromolecules in baboons

The effect of an intrauterine foreign body (IUFB) on the incorporation of acetate-1- 14C into endometrial lipids, RNA and protein was studied in baboons. Thirty minutes after the intraluminal instillation of the radioprecursor, the control endometrium was found to contain about three times as much total radioactivity as the IUFB endometrium. However, the percentage of total tissue radioactivity which was incorporated into tissue macromolecules was 3–5 times greater in the IUFB than in the control endometrium. The tissue content of RNA and protein per unit tissue DNA was significantly lower and the specific activities of RNA and protein were significantly higher in the IUFB than in the control endometrium. These findings suggest that an IUFB may stimulate the turnover of macromolecules in baboon endometrium.

ENDOMETRIAL RESPONSE TO THE INTRAUTERINE DEVICE

The endometriums from 50 hysterectomy patient specimens were studied morphologically and biochemically to determine the effects of the IUD. 13 examples of endometrial histology were selected at different stages of the cycle to illustrate typical changes associated with the use of the IUD. 4 of the cases are presented as controls to illustrate differences between those patients using the IUD and those using no contraceptive divice. Histopathologic findings indicate that the IUD has the effect of altering the synchrony of the endometrial maturation so that the endometrium is out of phase with the ovum when and if it reaches the endometrial cavity. Further support of this idea is derived from studies on endometrial lipids. On the basis of the analysis of endometrial lipid patterns it is suggested that the presence of an intrauterine contraceptive divice arrests or retards the biochemical maturation of the endometrium. An uterine environment unfavorable to implantation results from the failure to achieve biochemical maturation of the endometrium which is synchronous to that taking place in the ovum and in other sites of the neuroendocrine system concerned with implantation. It is concluded that the effectiveness of the IUD may be the result of interference with several factors in the reproduction process.

Endometrial response to the intrauterine device

The endometriums from 50 hysterectomy patient specimens were studied morphologically and biochemically to determine the effects of the IUD. 13 examples of endometrial histology were selected at different stages of the cycle to illustrate typical changes associated with the use of the IUD. 4 of the cases are presented as controls to illustrate differences between those patients using the IUD and those using no contraceptive divice. Histopathologic findings indicate that the IUD has the effect of altering the synchrony of the endometrial maturation so that the endometrium is out of phase with the ovum when and if it reaches the endometrial cavity. Further support of this idea is derived from studies on endometrial lipids. On the basis of the analysis of endometrial lipid patterns, it is suggested that the presence of an intrauterine contraceptive divice arrests or retards the biochemical maturation of the endometrium. An uterine environment, unfavorable to implantation, results from the failure to achieve biochemical maturation of the endometrium which is synchronous to that taking place in the ovum and in other sites of the neuroendocrine system concerned with implantation. It is concluded that the effectiveness of the IUD may be the result of interference with several factors in the reproduction process.